[1] Tattersall has concentrated his research over the past quarter-century on the analysis of the human fossil record and the study of the ecology and systematics of the lemurs of Madagascar,[3] and is considered a leader in both areas.

Tattersall claims that individual organisms are mind-bogglingly complex and integrated mechanisms; they succeed or fail as the sum of their parts, and not because of a particular characteristic.

This idea differs from the typical view that homo sapiens is the pinnacle of an evolutionary ladder that humanity's ancestors laboriously climbed.

As curator, he has also been responsible for several major exhibits at the American Museum of Natural History, including: Ancestors: Four Million Years of Humanity (1984), and Dark Caves, Bright Visions: Life In Ice Age Europe.

[1] He serves on the executive board of the Institute of Human Origins[5] and is a member of the Lemur Conservation Foundation's Scientific Advisory Council.